1979 Super Six start issues
Start with the basics
Is it fuel, spark or compression?
IS IT FUEL?
Remove the filter, use a flashlight if necessary, and look down the carb throat. Work the throttle and look for an instant stream of fuel from the acellerator pump. If nothing, crank for 5-10 seconds and try again.
IS IT SPARK?
It is IMPORTANT to understand that there are TWO sources of power for Mopar igniton........one with the key in "run" and one in "start."
Buy or rig a spark test gap in the coil wire. Test using the KEY. You should get a nice hot spark. If not, substitute something for the coil wire, as the coil wire might be bad
Remove and examine the plugs. Are they fuel fowled? oil fowled? What do they look like?
Inspect the interior of the dist. cap and the rotor, for moisture, grease, "strike damage," etc.
Is it COMPRESSION? (Or has the cam timing slipped?) Save this for last, but run a compression check. The service manual has procedures to estimate whether the timing chain has slipped